Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous environmental contaminants that adversely affect human health, mainly through their carcinogenic and mutagenic properties. Monitoring the exposure to PAHs of the inhabitants of air polluted regions is important because of the impact of these pollutants on human health. The aim of this study was to assess the exposure to PAHs of municipal police officers (non-smokers) living in three localities in the Czech Republic (strategically selected according to the level of air pollution) and determine how air pollution impacts personal exposure to PAHs via inhalation. Twenty PAHs were determined in the inhaled air collected from personal air samplers. Simultaneously, the total exposure to PAHs was investigated by evaluating the concentrations of 11 monohydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) in urine samples. Despite the observed differences in the concentrations of PAHs in the air from the personal samplers between the three locations, no statistically significant differences were found in the concentrations of OH-PAHs in the urine samples. Outcomes of this study indicate that inhalation exposure is not the primary source of PAHs exposure for Czech municipal police officers, but that diet may also be an important contributor to total body burden. The levels of OH-PAHs found in urine of Czech municipal police officers were very similar to those found in the urine of the Czech mothers from our previous study. This study provided the data about the body burden of potentially occupationally exposed group that has not yet been studied in the Czech Republic.

• Klíčová slova
• Air pollution, Biomonitoring, Czech Republic, GC–MS/MS, PAHs, Personal air samplers, UHPLC − MS/MS, Urine analysis,
• MeSH
• biologické markery moč   MeSH
• dospělí MeSH
• inhalační expozice * analýza   MeSH
• látky znečišťující vzduch * moč   MeSH
• lidé MeSH
• monitorování životního prostředí MeSH
• policie * MeSH
• polycyklické aromatické uhlovodíky * moč   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH
• Názvy látek
• biologické markery MeSH
• látky znečišťující vzduch * MeSH
• polycyklické aromatické uhlovodíky * MeSH

DNA methylation is the most studied epigenetic mechanism that regulates gene expression, and it can serve as a useful biomarker of prior environmental exposure and future health outcomes. This study focused on DNA methylation profiles in a human cohort, comprising 125 nonsmoking city policemen (sampled twice), living and working in three localities (Prague, Ostrava and Ceske Budejovice) of the Czech Republic, who spent the majority of their working time outdoors. The main characterization of the localities, differing by major sources of air pollution, was defined by the stationary air pollution monitoring of PM2.5, B[a]P and NO2. DNA methylation was analyzed by a genome-wide microarray method. No season-specific DNA methylation pattern was discovered; however, we identified 13,643 differentially methylated CpG loci (DML) for a comparison between the Prague and Ostrava groups. The most significant DML was cg10123377 (log2FC = -1.92, p = 8.30 × 10-4) and loci annotated to RPTOR (total 20 CpG loci). We also found two hypomethylated loci annotated to the DNA repair gene XRCC5. Groups of DML annotated to the same gene were linked to diabetes mellitus (KCNQ1), respiratory diseases (PTPRN2), the dopaminergic system of the brain and neurodegenerative diseases (NR4A2). The most significant possibly affected pathway was Axon guidance, with 86 potentially deregulated genes near DML. The cluster of gene sets that could be affected by DNA methylation in the Ostrava groups mainly includes the neuronal functions and biological processes of cell junctions and adhesion assembly. The study demonstrates that the differences in the type of air pollution between localities can affect a unique change in DNA methylation profiles across the human genome.

• Klíčová slova
• DNA methylation, air pollution, environment, epigenetics, molecular epidemiology,
• MeSH
• celogenomová asociační studie MeSH
• dospělí MeSH
• látky znečišťující vzduch škodlivé účinky   MeSH
• lidé středního věku MeSH
• lidé MeSH
• metylace DNA účinky léků   MeSH
• policie * MeSH
• vystavení vlivu životního prostředí škodlivé účinky   MeSH
• znečištění ovzduší škodlivé účinky   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH
• Názvy látek
• látky znečišťující vzduch MeSH

A DNA methylation pattern represents an original plan of the function settings of individual cells and tissues. The basic strategies of its development and changes during the human lifetime are known, but the details related to its modification over the years on an individual basis have not yet been studied. Moreover, current evidence shows that environmental exposure could generate changes in DNA methylation settings and, subsequently, the function of genes. In this study, we analyzed the effect of chronic exposure to nanoparticles (NP) in occupationally exposed workers repeatedly sampled in four consecutive years (2016-2019). A detailed methylation pattern analysis of 14 persons (10 exposed and 4 controls) was performed on an individual basis. A microarray-based approach using chips, allowing the assessment of more than 850 K CpG loci, was used. Individual DNA methylation patterns were compared by principal component analysis (PCA). The results show the shift in DNA methylation patterns in individual years in all the exposed and control subjects. The overall range of differences varied between the years in individual persons. The differences between the first and last year of examination (a three-year time period) seem to be consistently greater in the NP-exposed subjects in comparison with the controls. The selected 14 most differently methylated cg loci were relatively stable in the chronically exposed subjects. In summary, the specific type of long-term exposure can contribute to the fixing of relevant epigenetic changes related to a specific environment as, e.g., NP inhalation.

• Klíčová slova
• DNA methylation, epigenetics, human, microarrays, nanoparticles, occupational exposure, time changes,
• MeSH
• CpG ostrůvky MeSH
• dospělí MeSH
• epigeneze genetická * MeSH
• lidé středního věku MeSH
• lidé MeSH
• metylace DNA * MeSH
• nanočástice škodlivé účinky   MeSH
• nemoci z povolání chemicky indukované   epidemiologie   genetika   MeSH
• pracovní expozice škodlivé účinky   MeSH
• regulace genové exprese účinky léků   MeSH
• studie případů a kontrol MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika epidemiologie   MeSH

Small non-coding RNA molecules (miRNAs) play an important role in the epigenetic regulation of gene expression. As these molecules have been repeatedly implicated in human cancers, they have been suggested as biomarkers of the disease. Additionally, miRNA levels have been shown to be affected by environmental pollutants, including airborne contaminants. In this review, we searched the current literature for miRNAs involved in lung cancer, as well as miRNAs deregulated as a result of exposure to air pollutants. We then performed a synthesis of the data and identified those molecules commonly deregulated under both conditions. We detected a total of 25 miRNAs meeting the criteria, among them, miR-222, miR-21, miR-126-3p, miR-155 and miR-425 being the most prominent. We propose these miRNAs as biomarkers of choice for the identification of human populations exposed to air pollution with a significant risk of developing lung cancer.

• Klíčová slova
• air pollution, biomarker, exposure, human, lung cancer, miRNA,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Human data concerning exposure to nanoparticles are very limited, and biomarkers for monitoring exposure are urgently needed. In a follow-up of a 2016 study in a nanocomposites plant, in which only exhaled breath condensate (EBC) was examined, eight markers of oxidative stress were analyzed in three bodily fluids, i.e., EBC, plasma and urine, in both pre-shift and post-shift samples in 2017 and 2018. Aerosol exposures were monitored. Mass concentration in 2017 was 0.351 mg/m3 during machining, and 0.179 and 0.217 mg/m3 during machining and welding, respectively, in 2018. In number concentrations, nanoparticles formed 96%, 90% and 59%, respectively. In both years, pre-shift elevations of 50.0% in EBC, 37.5% in plasma and 6.25% in urine biomarkers were observed. Post-shift elevation reached 62.5% in EBC, 68.8% in plasma and 18.8% in urine samples. The same trend was observed in all biological fluids. Individual factors were responsible for the elevation of control subjects' afternoon vs. morning markers in 2018; all were significantly lower compared to those of workers. Malondialdehyde levels were always acutely shifted, and 8-hydroxy-2-deoxyguanosine levels best showed chronic exposure effect. EBC and plasma analysis appear to be the ideal fluids for bio-monitoring of oxidative stress arising from engineered nanomaterials. Potential late effects need to be targeted and prevented, as there is a similarity of EBC findings in patients with silicosis and asbestosis.

• Klíčová slova
• biomarkers, controls, exhaled breath condensate, nanoparticles, oxidative stress, plasma, urine, workers,
• Publikační typ
• časopisecké články MeSH

The exposure of living organisms to environmental stress triggers defensive responses resulting in the activation of protective processes. Whenever the exposure occurs at low doses, defensive effects overwhelm the adverse effects of the exposure; this adaptive situation is referred to as "hormesis". Environmental, physical, and nutritional hormetins lead to the stimulation and strengthening of the maintenance and repair systems in cells and tissues. Exercise, heat, and irradiation are examples of physical hormetins, which activate heat shock-, DNA repair-, and anti-oxidative-stress responses. The health promoting effect of many bio-actives in fruits and vegetables can be seen as the effect of mildly toxic compounds triggering this adaptive stimulus. Numerous studies indicate that living organisms possess the ability to adapt to adverse environmental conditions, as exemplified by the fact that DNA damage and gene expression profiling in populations living in the environment with high levels of air pollution do not correspond to the concentrations of pollutants. The molecular mechanisms of the hormetic response include modulation of (a) transcription factor Nrf2 activating the synthesis of glutathione and the subsequent protection of the cell; (b) DNA methylation; and (c) microRNA. These findings provide evidence that hormesis is a toxicological event, occurring at low exposure doses to environmental stressors, having the benefit for the maintenance of a healthy status.

• Klíčová slova
• adaptive response, microRNA machinery, preventive medicine,
• MeSH
• epigeneze genetická * MeSH
• fyziologická adaptace * MeSH
• fyziologický stres * MeSH
• hormeze * MeSH
• lidé MeSH
• oxidační stres MeSH
• poškození DNA MeSH
• regulace genové exprese MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

The risk of exposure to nanoparticles (NPs) has rapidly increased during the last decade due to the vast use of nanomaterials (NMs) in many areas of human life. Despite this fact, human biomonitoring studies focused on the effect of NP exposure on DNA alterations are still rare. Furthermore, there are virtually no epigenetic data available. In this study, we investigated global and gene-specific DNA methylation profiles in a group of 20 long-term (mean 14.5 years) exposed, nanocomposite, research workers and in 20 controls. Both groups were sampled twice/day (pre-shift and post-shift) in September 2018. We applied Infinium Methylation Assay, using the Infinium MethylationEPIC BeadChips with more than 850,000 CpG loci, for identification of the DNA methylation pattern in the studied groups. Aerosol exposure monitoring, including two nanosized fractions, was also performed as proof of acute NP exposure. The obtained array data showed significant differences in methylation between the exposed and control groups related to long-term exposure, specifically 341 CpG loci were hypomethylated and 364 hypermethylated. The most significant CpG differences were mainly detected in genes involved in lipid metabolism, the immune system, lung functions, signaling pathways, cancer development and xenobiotic detoxification. In contrast, short-term acute NP exposure was not accompanied by DNA methylation changes. In summary, long-term (years) exposure to NP is associated with DNA epigenetic alterations.

• Klíčová slova
• 850K microarray, CpG sites, DNA methylation, epigenetic adaptation, human, nanoparticles, occupational exposure,
• MeSH
• dospělí MeSH
• epigeneze genetická MeSH
• genom lidský MeSH
• lidé středního věku MeSH
• lidé MeSH
• metylace DNA účinky léků   MeSH
• mladý dospělý MeSH
• nanočástice škodlivé účinky   MeSH
• nanokompozity škodlivé účinky   MeSH
• pracovní expozice * MeSH
• senioři MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Thousands of researchers and workers worldwide are employed in nanocomposites manufacturing, yet little is known about their respiratory health. Aerosol exposures were characterized using real time and integrated instruments. Aerosol mass concentration ranged from 0.120 mg/m³ to 1.840 mg/m³ during nanocomposite machining processes; median particle number concentration ranged from 4.8 × 10⁴ to 5.4 × 10⁵ particles/cm³. The proportion of nanoparticles varied by process from 40 to 95%. Twenty employees, working in nanocomposite materials research were examined pre-shift and post-shift using spirometry and fractional exhaled nitric oxide (FeNO) in parallel with 21 controls. Pro-inflammatory leukotrienes (LT) type B4, C4, D4, and E4; tumor necrosis factor (TNF); interleukins; and anti-inflammatory lipoxins (LXA4 and LXB4) were analyzed in their exhaled breath condensate (EBC). Chronic bronchitis was present in 20% of researchers, but not in controls. A significant decrease in forced expiratory volume in 1 s (FEV1) and FEV1/forced vital capacity (FVC) was found in researchers post-shift (p ˂ 0.05). Post-shift EBC samples were higher for TNF (p ˂ 0.001), LTB4 (p ˂ 0.001), and LTE4 (p ˂ 0.01) compared with controls. Nanocomposites production was associated with LTB4 (p ˂ 0.001), LTE4 (p ˂ 0.05), and TNF (p ˂ 0.001), in addition to pre-shift LTD4 and LXB4 (both p ˂ 0.05). Spirometry documented minor, but significant, post-shift lung impairment. TNF and LTB4 were the most robust markers of biological effects. Proper ventilation and respiratory protection are required during nanocomposites processing.

• Klíčová slova
• FeNO, exhaled breath condensate (EBC), inflammation, nanocomposites, nanoparticles, spirometry,
• Publikační typ
• časopisecké články MeSH